Nature was not necessarily best.
A Grotto-Heaven was a creation that inevitably emerged once the Immortal Dao had developed to a certain degree. Cultivating within one meant facing far fewer shackles from heaven and earth than cultivating in an ordinary world.
Just as now, the many powerful factions of the Tianyuan Realm sent their own descendants into the Ancient Immortal Ruins to advance into the Purple Mansion Realm. This was because Purple Mansions advanced within the Ancient Immortal Ruins could draw closer to the primordial laws of heaven and earth from Taixu's beginning. When they later traveled to other worlds, they would not be constrained by the local world's petty village rules.
Of course, it was also because whether their descendants lived or died, succeeded or failed, they could leave behind an imprint, helping the Tianyuan human race keep the Ancient Immortal Ruins firmly in their grasp.
"Advancing into the Purple Mansion Realm here is indeed excellent for you. You'll have an advantage when you visit other worlds like the Dahuang Realm in the future, unaffected by the differences between heaven and earth. But it still can't solve the problem of being unable to use Immortal Dao power in the Huaixu Realm."
Fuxie was somewhat curious about An Jing's train of thought, but An Jing had long been prepared. "Over by the Heavenly Sword Mountain Range, where Kuji is sealed, isn't there a sealed Grotto-Heaven? Once we return to Huaixu, help me establish a connection. I'll entrust myself to that Grotto-Heaven."
"It is deeply connected to you. Using you as the guide and the altar, it can draw power over even mountains and rivers thousands of miles apart."
The Grotto-Heaven sealing Kuji was, in truth, of an exceptionally high grade. Not only did it contain all Yin and Yang and